Curry 1995.

Methods	Setting: HMO, USA Recruitment: smokers identified via a telephone survey of health behaviour in a random sample of HMO members (unselected)
Participants	1137 smokers, 53% female, average age 41, average cpd 17
Interventions	No face‐to‐face contact ∙ Control ‐ no materials ∙ Self‐help booklet (Breaking Away) with units to complete, relevant to all stages of readiness to quit ∙ As second bullet above plus feedback based on computer analysis of initial survey; included a handwritten form and a list of relevant parts of booklet ∙ As third bullet above plus up to 3 counsellor‐initiated phone calls (not included in this review)
Outcomes	Sustained abstinence 3 months to 12 months Validation: saliva cotinine requested but not obtained for all participants; disconfirmation rates not significantly different between groups
Notes	12 months' rather than 21 months' follow‐up used for comparability with other studies; study author confirmed numbers quit 2 vs 1 in self‐help vs control 3 vs 2 in effects of tailoring
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Randomised; method not described
Allocation concealment (selection bias)	Unclear risk	No details given
Blinding (performance bias and detection bias) All outcomes	High risk	Control group aware that they may be receiving materials or phone calls, which they did not receive; this could introduce performance bias "Collecting saliva cotinine...was challenging because participants had neither explicitly volunteered for a study of smoking behavior nor requested treatment for smoking cessation... nearly one fourth of those contacted refused to provide a sample" Higher disconfirmation in control group but difference not significant
Incomplete outcome data (attrition bias) All outcomes	Low risk	88% provided data at 3 months and at 12 months No difference in response rates across groups Missing counted as smoking in meta‐analysis